The present invention concerns a rotor machine arrangement, comprising a rotor, a stator, at least one guide vane, which at two opposite ends is supported by the stator, and at at least one end is pivotally arranged relative to the stator in at least a first plane, and at least one conducting member, arranged to conduct a fluid into the guide vane for influencing the temperature of the same.
Such arrangements are previously known in gas turbine arrangements, in which said fluid may be compressor air which has been drained off from a compressor included in the gas turbine arrangement, wherein the rotor machine arrangement in which said guide vane is provided is a turbine. The compressor air is used for cooling the guide vane from its interior. Small holes are arranged in the blade itself of the guide vane such that the compressor air is allowed to flow out from the same and into the gas flow channel of the turbine. Thanks to the cooling of the guide vane, too large temperature induced dimensional changes and heat influence on the material which shortens its life time may be reduced.
Usually the compressor air/cooling air is conducted through tubes and/or drilled holes in stationary stator parts to inlet chambers arranged at the two opposite ends of the guide vane. When the guide vane at both its ends is supported by the stator, or, more precisely, by guide vane carriers secured to the stator, the guide vane must be able to be tilted relative to surrounding stator parts because of the different axial movements which exist between the inner stator part which supports the one end of the guide vane and the outer stator part which supports its other end. By axial movements is meant movements in the axial direction of the rotor. Due to the fact that the pressure drop across the guide vane is large it is thereby difficult to avoid unwanted leakage of cooling air and gas around such tiltable, pivotable guide vanes. Leakage of compressor air which may not be used as cooling air into the gas flow channel of the turbine and leakage of gas out from the gas flow channel of course reduce the efficiency of the gas turbine arrangement.
The purpose of the present invention is to achieve a rotor machine arrangement of the initially defined kind which is arranged to prevent a fluid which is conducted into a guide vane for influencing the temperature of the same from leaking out between the stator and the guide vane even at different adjusted angles/pivotable positions between these in said first plane. Alternatively, a limited but controlled such leakage may be permitted, which leakage is essentially independent of said adjusted angles.
This purpose is achieved by means of a rotor machine arrangement as initially defined, which is characterised in that it comprises a sealing element which is pivotably connected with the guide vane in at least a second plane, is arranged to seal between the stator (11) and the guide vane (15), and the sealing function of which is essentially independent of the angular position between the guide vane (15) and the stator (11) in said first plane. The first and second planes are thereby preferably any of the planes in which the rotor axis of the rotor machine arrangement extends, here preferably parallel, and define preferably one and the same plane.
According to a preferred embodiment, the sealing element comprises a first sealing member arranged to seal between the guide vane and the sealing element, wherein the sealing function of said sealing member is essentially independent of the angular position between the guide vane and the sealing element in said second plane. Since the sealing element seals in this manner against the guide vane, a necessary condition for avoiding leakage of the fluid is given.
According to a further preferred embodiment, the sealing element is pivotably arranged relative to the stator in said second plane. The position of the sealing element may thereby be adjusted to a pivoting of the guide vane in the second plane in such a manner that the conditions for the function of the first sealing member will be good even at relatively large tilts of the guide vane relative to the stator.
According to a further preferred embodiment, the arrangement comprises a second sealing member, arranged to the seal between the sealing element and the stator, wherein the sealing function of said sealing member is essentially independent of the angular position between the sealing element and the stator in said second plane. The probability for a gas leakage or an air leakage via possible gaps between the surrounding stator parts and the movable component which the sealing element defines is thereby reduced.
According to a further preferred embodiment, the first sealing member comprises a bulge which extends around the outer circumference of the sealing element. The sealing element may thereby easily be constructed as a tube piece, arranged to be pushed into a recess of the guide vane, wherein the bulge, which preferably has a gently rounded outer periphery, may easily be formed in such a way that it allows a certain relative pivoting/tilting between the guide vane and the sealing element at the same time as it still sealingly abuts these. The bulge is preferably secured to and forms a part of the sealing element itself.
According to a further preferred embodiment, the second sealing member comprises a bulge, which extends around its outer circumference of the sealing element. It is preferably secured to and forms a part of the sealing element. It is thereby made possible to position the sealing element in a recess of the stator, preferably carrying members of the stator which are arranged to support the guide vane. The sealing element preferably has, in the area of said bulge, the shape of an essentially circular tube on the outside of which the bulge is provided. Such a design generates good conditions for both good sealing and relative movability between the sealing element and a recess in the stator, in which recess the sealing element is provided.
According to a further preferred embodiment, the sealing element comprises a cylinder body with an annular cross-section and with two annular bulges, each of which extends around the outer circumference of the sealing element and defines the first and the second sealing member, respectively. A sealing element with such a construction may easily be brought to abut guide vane carriers and recesses at end spaces of the guide vane. For example, a cooling medium/compressor air may via a chamber be conducted into the sealing element and via this element into the guide vane without any essential amount of the medium leaking out between the sealing element and the guide vane carrier into the flow channel of the rotor machine and without a gas to any larger extent leaks the opposite way. Furthermore, the cooling medium which has been conducted into the sealing element will be prevented from leaking out via some gap between the sealing element and a recess of the guide vane in which the sealing element is introduced.
According to a further preferred embodiment, the guide vane is pivotably arranged relative to the stator at both ends, a further conducting member is arranged to conduct the fluid influencing the temperature to the second end of the guide vane, and one sealing element with said first and/or second sealing member is arranged at each of the ends of the guide vane. A very good supply to the guide vane of for example cooling air from a compressor included in the rotor machine arrangement or connected thereto is thereby achieved at the same time as a possible leakage of cooling air outside of the sealing elements and into the gas flow channel of the turbine is kept at a reduced level.
According to a further preferred embodiment, the rotor machine arrangement comprises a plurality of guide vanes, arranged in a ring and each of which is connected with said conducting member, wherein first and/or second sealing members are arranged at each of the guide vanes. Such an arrangement is in particular advantageous when the rotor machine arrangement comprises a turbine, where said ring of guide vanes is the first of a plurality of rings as seen in the flow direction of the turbine and said ring is arranged in the area of an inlet to the turbine, where the gas flowing in is very hot, has a high pressure and where the individual guide vanes at two opposite ends are attached to a radially outer and a radially inner stator part.
Further features of and advantage with the rotor machine arrangement according to the invention will be clear from the following description and from the appendant claims.